<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="js/jquery-3.3.1.min.js"></script>
    <script>
        $(function(){
            $('#hello').css('color','red')

            $('.world').css('color', 'blue') // 隐式迭代

            $('div').css('background', 'pink')

            $('div > span').css('font-size', '40px').css('color', 'green').css('text-decoration', 'underline') // 链式编程
        })
    </script>
</head>
<body>
    <div id="hello">aaaa</div>
    <p class="world">bbbb</p>
    <span class="world">cccc</span>
    <div>dddd</div>
    
    <div>
        <span>eee</span>
    </div>

    <div>
        <p>
            <span>fff</span>
        </p>
    </div>
</body>
</html>